Circuit-closer for gas-alarms.



A. DI LEGGE.

cmcun CLOSER FOR 01s ALARMS APPLICATION FILED MAY I4. 1914.

Patented May 30, 1916.

ABM ANDO DI LEGGE, OF NEW YORK, N. Y.

CIRCUIT-CLOSER FOR GAS-ALARMS.

Specification of Letters Patent.

Patented May 30, 1916.

Application filed May 14, 1914. Serial No, 838,423.

To all whom 21 may concern:

Be it known that L'AR'MANDQ DI Laser, 9. subject of the King of Italy,residing in the borough of Manhattan, city, county, and State -.of NewvYork, have invented certain new and useful Improvements in Circuit-Closers for Gas-Alarms, of which the following is aspecificatiom'reference being bad tothe accompanying drawings.

I This invention relates to improvements in circuit closers for devicesfor giving an alarm when there is present a dangerous mixtureofpoisonous gas (such as illuminating gas) and air; and an object of thisinvention is to provide a circuit closer -for gas alarms which will besimple in construction, comparatively cheap in manufacture andeliicient, reliable and sensitive in operation and use.

"2 In the drawings illustrating the principle of this invention and thebest mode now known to me of applying that principle, Figure 1 is aneievat-ion,of no new circuit closer for gas alarms; is a detail showingthe support for'the circuit-making lever; and Fig. 3 is a diagrammaticview of a simplified construction.

Upon the baseboard a are mounted the coils b of an electro-magnet cthecores d ,goof which are opposed to the armature e.

This armature e is fastened to a flexible strip gor leaf-spring fbywhich the armature is -Qsuspende from the bracket g. The lower end ofthe armature c carries the striker h 35 which is arranged to strikeagainst the bell or gong i when the electro-magnet c is energized. Onepole of an electric battery (or othersour ce of current) is connected tothe binding-pdst while the other pole of the same battery (not shown) isconnected to the binding-post 70. One end of the coils or spools Z1 isconnected to the binding-post 7' by the ,wire m while the other end ofthese coils b (which are in series) is connected by (5 the wire 11.tothe post 0. Through a threaded hole in the latter there is screwed acontact-pin p which normally contacts with a leaf-spring g that isfastened to the armature c. From the binding-post 70 there leads to abranch or divide circuit as follows: The .wire 1' joins elect cally thebinding-post k to the contact-plate 8. Uponthe bracketplate It there ispivoted a circuit-making leven or automatic switch it to which is attfitached one end of a spring or the other end of which is fastened tothebracket-plate t.

The toe u of the lever u normally rests upon a pin w which projects fromthe armature e and is supported by the pin w, so that the circuit isnormally kept open. When, however, the armature e is attracted by theelectro-magnet c, the toe u is de-- prived of the support of the pin w,whereupon the spring w pulls up thearm u" of the lever u and brings itinto contact with the plate 8, and at the same time the toe u is throwninto electrical contact with the post 0. The other branch of the dividedcircuit fronnthe binding post It comprises the connectiiig wire in whichjoins electrically the binding post is and the plate y in which there ismounted the. screw 2 susceptible of being given a fine adjustment. Inthe bracket 2 there is fastened one branch or leg 3 of an L-shapedbi-metalliostrip 3. This bi-metallic strip is preferably made of stripsof zinc and steel soldered together.

he zinc strip 4 is on the outside (that is, on the left of the leg 3 asshown in Fig. 1) while in the horizontal part or arm 6 of the L-shapedstrip, the steel strip 5 lies on the outside (that is, on the upperside, as the arm 6 is shown in Fig. '1). The arm 6 pro-- jects beneaththe lower end of the screw 2 and is separated therefrom by a shortdistance. To the arm 6 there is, bound by palladium wire 7 sma 1 bits 8of oxid of palladium and small bits 9 of porous charcoal,

- which may be made by extinguishing a piece of burning wood by plungingthe same in mercury. As shown in Fig. l, the exid of palladium 8 and thecharcoal 9 is bound to the lower or zincstrip side of the iii-metallicarm 6. The bracket 2 is connected by the wire 10 with the bracket-plateg.

The operation of the gas-alarm hereinbefore described is as follows:When the proportions of gas and air have become substantially one partof gasin one hundred parts of air, the charcoal and the oxid ofpalladium absorb the gas with evolution of heat. This heat istransmitted to the bi: metallic arm 6. The coeiiicientof expansion dueto heat is greater in the case of zinc than of steel; and since the zincstrip 4 is soldered to the steel strip 5, the extension of the zincstrip results in the free end of the arm 6 curving toward the point ofthe screw 2; and when the proportion of gas has thus become sufiicientlygreat, this curvature of the free end of the arm 6 becomes so great thatcontact is made between the screw 2 In the leg 3" of its support. Thespring '0 and the arm 6, tric circuit through the coils of theelectromagnet c. The armature e is now attracted, whereby the toe u ofthe lever u is deprived pulls up the arm a into contact with the plate aand throws the toe u into contact with the post 0. This makes throughthe other branch of the divided circuit and the bell will continue toring. Of

course, the bell may be placed at any desired} point where it is desireda poisonrepresentation of the electrical connections of a simplifiedform of the apparatus. The

binding-post j is connected by the Wire m with the bracket 2 in which isfastened the leg 3 of the L-shaped bi-metallic switch to the arm 6 ofwhich there are fastened, as before, bits of carbon and oxid ofpalladium diagrammatically shown at 8. The bracketplate 2' is connectedby a wire 2 with a condenser 11 which is connected by a wire y with aplate 3/ in which is mounted the screw 2. The contact-plate 3 isconnected by a wire 5: with the electric bell 2', which is,

by the wire is", connected to the post is.

thereby completing the elecor completes the circuit "room temperature.

The arm 6 ispreferably made about twice the len strip. .he leg 3 of thelatter taites no ac tive part in the closing of the circuit, when anescape of gas occurs. The function of this leg 3' is to compensate orneutralize the variation in length of the arm 6 due to temperaturechanges that daily, even houriy, take place in the atmospheresurrounding the instrument as whole, or in short, due to variations inwhat is commonly known as When gas escapes, the arm 6, which carries thegas-absorbing mass 8, 9, is the active element in the eiosing of thecircuit through the alarm bell, in which function the leg 3' does notparticipate at all except as a mere conductor.

I claim:

In a gas-alarm, a pair of ciTomi-terminals; a bent bimetallic switch(l"i0fi having two branches in which the position of the state isreversed, the end of one of said branches being normallyout of contactwith one of said circuit-terminals; and a gas-abmrbing -mass which inthe presence of gas imparts heat to the last-named branch and causes thesame to expand and close the circuit between said terminals.

In testimony whereof I have hereunto set I my hand at the borough ofManhattan, city. county and State of New York this ninth day of May, A.D., 1914, in the presenceof the two. undersigned witnesses.

' ARMANDO D1 LEGGE. Witnesses: ARMANDO Bacon,

Keno MICHELE.

h of. the leg 3 of the iii-metallic

